Method and apparatus for cleaning



Sept. 3, 1935 K. STEINBACHER METHOD AND APPARATUS FOR CLEANING FiledAug. 23, 1934 2 Sheets-Sheet INVENTOR Sept. 3, 1935. K. STEINBACHER2,013,511

METHOD AND APPARATUS FOR CLEANING Filed Aug. 23, 1954 2 Sheets-Sheet 2[g3 kgfin NVENJI'OR i Patented Sept. 3, 1935 UNITED STATES TENT FIE

12 Claims.

My invention relates to the cleaning of checkerwork structures and, inparticular, those designedfor the absorption, storage and delivery ofheat.

The present tendency in the construction of checkerwork for heattransfer is to make the passages through the checkerwork smaller andsmaller in order to obtain better contact of the heating gases with therefractory composing the checkerwork. While this construction increasesthe efficiency of heat transfer, it presents a new problem of adifferent sort.

It is well known that checkerwork subject to a gas blast will collectparticlesborne by the blast to an extent such that the function of thecheckerwork, such as heat absorption or delivery, is seriouslyinterfered with. The problem is particularly acute in blast furnacestoves because of the fact that the blast furnace gas which is used forheating usually carries with it a considerable percentage of fines.

' Whilev gas cleaning apparatus is known, the cost of equipment capableof cleaning the volume of gas traversing the blast furnace stove to theextent necessary to avoid the objectionable deposit above mentioned, isprohibitive.

It has been the practice heretofore to clean checkerwork, such as that,installed in blast furnace stoves, by air or steam jets. Checkerwork,from its very nature, is not well adapted for cleaning by such meansbecause it is constructed to diffuse the gas traversing it and naturallyoffers considerable frictional resistance to flow therethrough. It hasbeen found that air and steam jets are capable of cleaning only alimited depth of the checkerwork. This naturally leaves the dirt removedfrom the upper layers so congested in the middle layers as almost toclose the checker openings. There is, furthermore, an ever-presenthazard to operatives using such jets.

Other expedients, such as pushing rods through the checkerwork ordropping chains or. weights through the openings therein, have beenresorted to in an effort to clean the lower depths of the checkerworkmore efiectively. This manner of cleaning checkerwork, however, involvesa great deal of hand labor and is tedious and time-consuming and, atbest, is efiective only to a limited degree.

I have invented a novel method and apparatus for cleaning checkerwork toremove accumulations of blast-borne material therefrom, which, avoid theobjections to the means and methods previously employed for thispurpose. In accordance with my invention, 1 isolate the checkerwork fromthe source of the gas normally traversing it, and flush the checkerworkwhencold, with a liquid such as water, draining off the water andaccumulations entrained therewith. After thorough flushing in thismanner, the checkerwork, after drying out, may be restored to service ina relatively short time. The apparatus comprises a header or manifoldadapted to be suspended above the checkerwork, the manifold havingflexible conduits extending therefrom adapted to be inserted in theopenings'in the checkerwork to conduct the flushing liquid therethrough.

A more complete understandingof the invention will result from aconsideration of the accompanying drawings and the following descriptionhaving reference thereto. In the drawings:

Figure 1 is a vertical sectional view through a blast furnace stove,showing diagrammatically the checkerwork therein, and the preferredembodiment of the invention in position for use;

Figure 2 is a perspective view to enlarged scale showing the apparatusand the manner of its use;

Figures 3, 4, 5 and.6 are horizontal sectional views taken through thecheckerwork at the planes indicated by the correspondingly numberedlines, showing one form of checkerwork construction and indicating thecharacter of the openings in the checkerwork at various levels; and

Figure 7 is an elevation of a portion of the apparatus, with part of thecheckerwork in section.

Referring now in detail to the drawings, the invention will be describedas applied to the cleaning of checkerwork in a blast furnace stove Ill,although it is to be understood that it is applicable to the cleaning ofvarious types of checkerwork, regardless .of their function or place of.installation. The stove I0 is of usual construction including a metallicshell II, a refractory lining H, a dome I3, and checkerwork indicatedgenerally at M. furnace, is admitted through a valve l5 to a combustionchamber I6, which is simply an enlarged vertical passage formed by abaflle wall Ilia extending upwardly toward'the dome. A chimney valve I!controls'the discharge of hot gases from Heating gas, usually from ablast I} the stove. The dome 13 has an opening l8 commonly closed by aplug and cap. Cold and hot blast valves are indicated at I9 and 20,respectively.

Figures 3, 4, 5 and' Gindicate the character of The size of the openingsin the checkerwork decreases as the gas descends through the stack, andthe character of the openings is such as to provide for the maximum areaof contact between the refractory brick composing the checkerwork andthe gases passing through the openings therein.

The brick in the upper levels of the checkerwork are as shown in Figure3 and have a vertical hole therein. The next section is formed by brickas shown in Figure 4 having similar openings with diagonal baffles. Thenext section is composed of similar members, the baflies being disposedin the opposite direction, as shown in Figure 5. The bottom section ofthe checkerwork has cruciform bailles disposed in the openings of thebrick, as shown in Figure 6.

The limiting factor upon the capacity of the stove, of course, is thearea of the brickwork exposed to the heating gas.

The construction described in detail so far is not part of my inventionbut is well known in the metallurgical art; It will be apparent that theremoval of fines deposited on checkerbrick, such as shown in Figures 3through'fi, at a depth as great as 30 or 40 feet, presents a diflicultproblem, particularly since the checkerwork is the heart of the stove,representing an investment of many thousands of dollars, and the factthat the brickwork is normally maintained at very high temperatures.Under the circumstances, the checkerwork must be guarded againstdeleterious influences insofar as possible in order to prolong its lifeto the utmost.

After the checkerwork has been heated to incandescence by the hot gasesflowing therethrough from the combustion chamber, the burner l5 and thechimney valve I! are closed. The cold blast valve l9 and the hot blastvalve 20 are then opened and cold air is delivered through the former tothe checkerwork and is discharged 4 through the valve 20 to the pointwhere the hot air is required, usually the heating or melting chamber ofa metallurgical furnace. When the checkerwork has been partially cooled,the process is repeated.

The layer of fines collecting on the checkerbrick during normal use,acts as an insulator to prevent the efiicient absorption and delivery ofheat by the checkerwork. The problem is particularly acute in newerinstallations where the openings through the checkerwork are smaller andthe diffusion of the gas is greater, in order to provide a greater areaof contact. It is practically impossible to .clean these later types of.

checkerwork installations by methods in use heretofore on installationsin which the diffusion of the gases and the reduction in the size of theopenings in the checkerwork were not carried to such an extent as atpresent.

My invention contemplates the use of a 'manifold 2| adapted to besuspended within the dome.

ill of the stove l0. It may conveniently be inserted through the opening18 on removal of the plug and cap (not shown).

and cleaning action. Hotwater also dries. out from the checkerwork morequickly than cold. Flexible conduits, for example hose lines v,23, are

connected to the manifold 2l= in such manneras.

The manifold 2| is; connected-by a pipe 22 to a source of liquid, suchas water; A steam line 22a connects tothe pipe '22 to heat the water soas to increase its solvent ported substantially perpendicular bysupports 24 illustrated in detail in Figure 7. These supports comprise avertical member'25, and a cross member or yoke 26 secured thereto. Thelower end of the uprights 25 are preferably provided with shoulders 21whereby the uprights may be placed in the openings in the checkerbrickand supported thereon, being capable of ready movement from place toplace as desired.

When it is necessary to clean a checkerbrick installation, I isolate itfrom the sources of the gases normally traversing it, and permit thecheckerwork to cool, if heated, to a temperaturesuch that workmen canconveniently operate in the vicinity. In the particular application ofthe invention to blast furnace stoves, I close valves l5, l1, l9 and 20,and position the manifold within the dome in about the position shown inthe drawings, and insert the hose lines into the openings in thecheckerbrick. By turning on the water, a cleansing flow passes into anddown throughthe checkerwork, washing all accumulations of dust and finestherefrom, not only by reason of the volume and velocity of the Water,but also by its solvent action. The result is that the checkerwork isvery thoroughly cleaned. The entire mass of brick is subjected tosimilar treatment by moving the hoselines from brick to brick throughoutthe area of the top layer. The supports 24, of course, are moved withthe hose lines, as may be necessary. The wash water and particlesentrained therewith fiows out at the bottom of the stove through a drainport 28.

It will be apparent from the foregoing that the invention provides amethod and apparatus for cleaning the checkerwork which is far superiorto anything proposed for that purpose hereinstallation shortened. Thewater streams descending through the checkerwork penetrate every crevicethereof and effect a thorough cleaning operation such as could notpossibly be obtained by mechanical means, since the points on the lowerpart of the structure where the fines accumulate most thickly cannot beseen or otherwise reached. The congestion of the dirt in the middle orlower part of the checkerwork resulting-from the use ofsteam or airjetsis avoided. The invention makes it possible to utilize the newertypes ofcheckerworks having small openings therein providing greatersurface area for heat transfer. These installations would otherwisebecome entirely useless after a certain length of time, because of thecollection of the insulating layer of fines therein and theimpossibility of cleaning the checkerwork by the means now known. Insome still newer types of checkerwork, furthermore, the bricks aredesigned to introduce a certain turbulence into the gases flowingtherein. These structures absolutely prevent the introduction ofmechanical means reproximately one-fifth the time necessary with 75 theair or steam jets and mechanical means. As previously stated, therefractory brick is hardly affected appreciably, since the waterabsorbed is easily removed by drying the brickwork prior to reheating itto operating temperature. This drying may be conveniently accomplishedby circulating slightly warmed' air through the checkerwork at arelatively low velocity.

As an instance of the efiectiveness of the invention, it has been usedon a blast furnace stove after the latter had been cleaned as well aspossible by previously known methods and apparatus. The use of theinvention on a stove so cleaned removed a great deal of additional accumulation which had not been touched by the mechanical means or thehigh velocity air and steam jets.

Although I have illustrated and described herein but a preferredpractice of the invention and a typical embodiment of the apparatusincident thereto, it willbe apparent that many changes may be made inthe method and apparatus without departing from the spirit of theinvention or the scope of the appended claims.

I claim: 7

1. In a method of removing accumulations of blast-home matter fromrefractory checkerwork adapted to be traversed by a gas blast, the stepsincluding isolating the checkerwork from the source of gas, and flushingthe checkerwork with water in sufiicient volume and at sufllcient.velocity to carry the accumulations through and away from thecheckerwork.

2. The method defined by claim 1 characterized by the furtherpreliminary step of cooling the checkerwork substantially to atmospherictemperature before flushing.

3. The method defined by claim 1 characterized by the further final stepof drying the checkerwork after flushing, prior to reheating it tooperative temperatures.

4. In a method of freeing regenerative checkerwork from accumulations ofblast-home particles, the steps including isolating the checkerwork fromassociated sources of gas, directing streams of water downwardly throughthe checkerwork, and draining the water and accumulations entrainedtherewith from below the checkerwork.

' 5. In a method of cleaning the checkerwork in blast furnace stoves,the steps including cutting the stove out of service, flushing thecheckerwork with water, and drying the checkerwork before reheating itto operative temperatures.

6. In a method of removing accumulated fines from checkerwork subject togas blasts, the steps including cutting off the blasts, flushing thecheckerwork with water, and draining the water and entrainedaccumulations.

7. In a method of cleaning regenerative checkerwork, the steps includingflushing it with-wathe flexible conduits as to maintain themsubstantially vertical at their points of entry into the checkerwork.

9. A hose support for a checkerwork cleaning apparatus comprising anupright having its lower end shaped to enter and engage a checkerbrick,said upright having means thereon for engaging and supporting a hose.

10. The apparatus defined by claim 9 wherein said hose-engaging andsupporting means comprises a cross member secured to said upright.

11.In a method of cleaning checkerwork, the steps including subjectingit to the action of a flow of water in suflicient volume and atsufllcient velocity to carry away fines deposited thereon.

12. In a method of removing accumulated dirt from the checkerwork ofblast furnace stoves, the steps including discharging water into thecheckerwork from adjacent the top of the stove, and draining the waterand removed dirt from the lower partof the stove.

KARL S'IEINBACHER.

